Fixing Safeco Field's roof

Safeco Field's 11,000-ton retractable roof has turned out to be hard on its feet.

The $40 million roof is so heavy that it keeps squishing out the rubber that provides padding between sets of rails and 128 steel wheels that roll the roof open and closed.

The rubber padding was supposed to absorb vibrations and muffle any steel-on-steel noise whenever the roof moves. But the rubber has oozed out under the weight of the roof since the stadium opened in 1999, said Kevin Callan, executive director of the Major League Stadium Public Facilities District, the public authority that oversees stadium operations.

Stadium officials have tried replacing the rubberized absorbers and installing clips to hold the padding in place, but to no avail. This spring, engineers tested other materials, and the solution seems to be a thin layer of galvanized steel no thicker than about one-quarter inch.

"It seems to work," said Scott Jenkins, the Seattle Mariners' vice president of ballpark operations.

Jenkins oversaw construction at Miller Park, Milwaukee's baseball stadium that also has a retractable roof, and said the stadium there has had similar problems.

Jenkins said at Safeco, the 275-foot-tall roof probably could go without the noise-muffling pads. But without something filling in the gap designed for the pad, the Safeco Field roof could be damaged when it opened or closed.

The roof repair is an example of unanticipated capital repairs, replacements, improvement and upgrades that go on each year at the 47,000-seat baseball park. Stadium officials are spending a total of $715,000 on those projects this off-season. The roof pads are the most expensive item, costing $350,000.

The stadium also is slated for $1.7 million in routine maintenance and capital improvements in 2008, everything from new communications and broadcast equipment to new dugout paint, new furniture and improvements in the children's playfield area.

Most of the unanticipated costs are designed to fix problems unexpected when the stadium was designed and built, said Callan. In the past, workers added an additional outfield stairwell and glass glazing to block swirling wind in parts of the stadium. This year, the stadium also is adding more security cameras, a sprinkler system for the scoreboard enclosure and a new field drainage system to help solve chronic flooding in the clubhouse areas.

"Every year you think you are done with it, and every year something else comes up," said Callan.

The Mariners are footing the bill, but the team ultimately will be reimbursed from a 5 percent admissions tax assessed by King County, Callan said.

The pads are being replaced during the off-season by Ederer LLC, the Seattle crane company that designed and built the retractable roof's wheel systems and controls.

Seattle Mariners President Chuck Armstrong told the Public Facilities District board that the use of the retractable roof has increased since the stadium opened. In 2000, Safeco's first full baseball season, the roof was closed or moved for 14 percent of the games. In 2005, the figure was 27 percent. This season, the roof was used about 25 percent of the time.